Recently, as various biosensors utilizing a special catalytic action of an enzyme are being developed and being applied to the clinical field, a biosensor for rapidly and accurately testing and determining the quantity of a specific component in a sample is being put to practical use.
Nowadays, a number of diabetic patients are significantly increasing, and regarding glucose, for example, a very complicating procedure of centrifuging blood and measuring plasma as a sample are conventionally required to measure and manage the blood sugar level, and thus a biosensor for measuring a whole blood is desired and is being put to practical use.
Such biosensors include that disclosed in for example, JP-A 61-294351 (1986), in which a predetermined voltage is supplied to an electrode system of a sensor applied with the whole blood, a current value flowing between the electrodes is measured, a glucose concentration in a sample solution is calculated based on the measured value, and the value thereof is displayed on a display unit of a dedicated measuring instrument.
A biosensor dispensing device, in which a sensor pack or a sensor bottle set with a plurality of biosensors is installed in a measuring instrument, for dispensing the biosensors one by one is disclosed. By virtue of such a biosensor dispensing device, even users such as diabetic patients that are mostly elderly are less likely to perform a wrong operation such as accidentally dropping the biosensor when installing, attaching in an opposite direction, or further, performing measurement with the device attached in the opposite direction.
The biosensor dispensing device disclosed in JP-A 8-262026 (1996) includes a substantially circular plate-shaped sensor pack 202 inside a housing 201 formed by attaching an upper case and a lower case in a freely opening and closing manner like a bivalve shell, as shown in FIGS. 19A and 19B. The sensor pack 202 contains a blood-glucose sensor in each of a plurality of sensor holding cavities and is communicated with a desiccant cavity. A sliding latch 203 for operating a sliding actuator is arranged in the upper case, and by sliding the sliding latch 203 with a thumb, the device can be set to a display/data processing mode or a test mode.
By, for example, arranging the sliding latch 203 to a display position of lateral decubitus and then pushing the latch towards the front of the housing, the device is set to the display/data processing mode, thus allowing the user to see the data displayed on a display 204 arranged in the upper case, or besides inputting data to an electrical component within the housing, to perform a command to obtain information related to the test being performed with a manual button 205 arranged adjacent to a data port connector on a rear part of the housing.
Alternatively, by arranging the sliding latch 203 to the test position of lateral decubitus and then pushing the latch towards the front of the housing, the device is set to the test mode. The biosensor is thereby discharged from one of the sensor cavity of the sensor pack 202 and pushed out from a test end 206 of the housing 201, and an electrical contact point on the biosensor is connected to a microprocessor and/or other data processing circuit within the housing. Thus, by applying the sample such as blood to the pushed out biosensor, the user can take out the data relating to the sample, and display the data on the display 204, or can store the data for transmission to other monitoring or analyzing apparatuses via the data port connector.
After the test is finished, the sliding latch 203 is pushed towards the back of the housing and is arranged in an original stand-by position, and the biosensor used in the test is discharged from the housing and the sensor pack 202 is rotated so that the non-used biosensor is moved from the test end 206 to the push-out position.
A biosensor dispensing device disclosed in JP-A 08-285858 (1996) has a sensor bottle 300 shown in FIG. 20A installed therein. In a bottle case 301 of the sensor bottle 300, a plurality of biosensor storing chambers 301a, desiccant storing chambers 301b, and flow paths 301c for communicating the biosensor storing chamber 301a and the desiccant storing chamber 301b are formed. An aluminum seal 302 and an aluminum seal 303 are adhered to both end faces of the bottle case 301, where one biosensor (not shown) is stored in each biosensor storing chamber 301a and one desiccant (not shown) is stored in each desiccant storing chamber 301b, and the desiccant absorbs the moisture entering the biosensor bottle 300, thus preventing a change in performance of the biosensor.
As shown in FIG. 20B, when the biosensor bottle 300 is installed in the biosensor dispensing device including a rotating shaft 305 and a pushing shaft 306, a biosensor bottle driving motor is activated, thus rotating the rotating shaft 305 in one direction and setting the biosensor bottle 300 to an initial position. The rotation of the rotating shaft 305 is performed while checking the position thereof with a photo-sensor (not shown).
When a measuring button (not shown) is pressed, a pushing shaft driving motor is activated, thus sliding the pushing shaft 306 to the left, which pushing shaft 306 then breaks through the aluminum seal 303 and pushes the biosensor 304. The pushed biosensor 304 breaks through the aluminum seal 302 and moves to a predetermined position and is then measured.
When the measuring button is pushed again after the measurement is finished, the pushing shaft driving motor is activated, thus sliding the pushing shaft 306 slightly towards the left and discharges the biosensor 304 out of the device. The pushing shaft driving motor is thereafter reversed, thus sliding the pushing shaft 306 to the right and returns the shaft to its initial position. The biosensor bottle driving motor is then activated, thus rotating the biosensor bottle 300 to a position at which a next biosensor 304 can be pushed out.
However, in the biosensor dispensing device disclosed in JP-A 8-262026 (1996), since the user must grip and take out the biosensor held at the test end 206 each time the test is finished and, since samples such as blood are applied to the used biosensor, the biosensor is, in the present state, held with for example, a paper and thus is not only complicating, but hygienic problems arise.
Further, since the sensor pack 202 can be loaded to an arbitrary position with respect to the housing 201, an incorrect loading sometimes occurs. That is, when the sensor pack 202 currently being used is taken out for some reasons and a new biosensor is loaded, the sensor pack 202 is sometimes loaded with the sensor holding cavity not containing the biosensor corresponding to the test end 206. In such a case as well, the device starts the operation without recognizing the incorrect loading, and thus the user performs the latch operation a number of times unnecessarily.
Moreover, when setting the device to the display/data processing mode or the test mode, the sliding latch 203 is sled in two-steps, as mentioned above, and thus wrong operation may occur, which is very inconvenient for the user. A cutter (not shown) for discharging the biosensor in the sensor pack 202 is arranged in the housing 201, and thus the user may hurt oneself when loading.
In the biosensor dispensing device disclosed in JP-A 08-285858 (1996), a plurality of sets each including the biosensor storing chamber 301a for storing one biosensor 304, the desiccant storing chamber 301b for storing one desiccant, and the flow path 301c for communicating both chambers, are formed around a center through-hole 301f, and thus the thickness of the biosensor bottle 300 becomes thick even if the number of biosensors 304 stored is few, and the dispensing device including the biosensor bottle 300 can not be made thin.
To appropriately push out and set the biosensor 304 from the biosensor bottle 300 installed in the device, an accuracy of position between the biosensor bottle 300 and the biosensor dispensing device must be set very severely.
When, after removing the biosensor 300 from the device, reloading the biosensor 300 and using such a biosensor, the biosensor bottle 300 is set to the initial position, and thus a setting operation of the biosensor 304 must be sequentially performed from a first biosensor storing chamber 301a, corresponding to the initial position, a second biosensor storing chamber 301a and so on, which in practice, produces a wasteful time until the biosensor 304 is pushed out and set.
Further, since the aluminum sheets 302, 303 are adhered to the end faces of the biosensor bottle 300, there is a danger that the aluminum sheets 302, 303 may be damaged during handling. On the other hand, the biosensor 304 must be able to easily break through the aluminum sheet 302 and be taken out. To this end, a distal end 304a of the biosensor 304 is pointed, and thus when applying the blood, the user may touch the edge thereof and feel pain. The distal end 304 of the biosensor 304 may be a square even if it is hard to break through the aluminum sheet 302, but a point to where the blood should be applied is hard to recognize with a square, and thus is inconvenient.
The present invention aims to provide, in order to solve the above problems, a compact biosensor cartridge and a biosensor dispensing device in which biosensors can be set with a simple operation so that they can be tested one by one, and are protected from moisture until they are set.